A new local anesthetic namely (S)-(-)-1-propyl-2',6'-pipecoloxylidide hydrochloride is described in WO 85/00599. The new compound has an unexpected long duration compared to the racemate and the corresponding (R)-(+)-enantiomer. The preparation method described in WO 85/00599 gives however a product which contains about 10% of the (R)-(+)-enantiomer. This means that the product from a physical chemical point of view, contains only about 80% of the (S)-(-)-enantiomer, while the residual about 20% constitutes the racemic form. In addition the product obtained is hygroscopic and thus not stable and contains about 2% of water. One mole of water of crystallization implies a water content of 5,5%. A product having a varying content of water has the drawback that the percentage of water must be analyzed each time a pharmaceutical formulation shall be prepared. As the (S)-(-)-enantiomer is the most potent enantiomer a product containing less (R)-(+)-enantiomer was wanted. One object of this invention is thus to produce the compound in a form, which is stable and which does not change by storing at ordinary room temperature and humidity. A second object of this invention is to obtain a product consisting of the substantially pure (S)-(-)-ennantiomer.